问题 解答题
用递等式计算.
①2450-450÷18×25
2
5
×
1
2
+
9
10
÷
9
20

5
16
+(
7
16
-
1
4
)÷
1
2

1
15
÷[(
2
3
+
1
5
)×
1
26
].
答案

①2450-450÷18×25,

=2450-25×25,

=2450-625,

=1825;

2
5
×
1
2
+
9
10
÷
9
20

=

1
5
+
9
10
×
20
9

=

1
5
+2,

=2

1
5

5
16
+(
7
16
-
1
4
)÷
1
2

=

5
16
+(
7
16
-
4
16
)×2,

=

5
16
+
3
16
×2,

=

5
16
+
6
16

=

11
16

1
15
÷[(
2
3
+
1
5
)×
1
26
],

=

1
15
÷[(
10
15
+
3
15
)×
1
26
],

=

1
15
÷(
13
15
×
1
26
),

=

1
15
÷
1
30

=

1
15
×30,

=2.

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